Mario Party on Mupen64

Hello, I'm new here to the forums. I was wondering if someone could help me with an issue I am having:

So recently, I was playing Mario Party online with a friend using netplay on Mupen64++. Everything was running smoothly until we got to the end. When the game was completed, I started getting errors saying that there was a missing plugin. This occurred while the ending cutscenes to the boards were playing, and didn't stop until the emulator crashed. If anyone has had a similar issue like this and knows a solution to fix this problem, please message me right away. I really would like to play more Mario Party with my friend without there being any issues.